drm/i915: Defer adding preallocated stolen objects to the VM list

When preallocating a stolen object during early initialisation, we may
be running before we have setup the the global GTT VM state, in
particular before we have initialised the range manager and associated
lists. As this is the case, we defer binding the stolen object until we
call i915_gem_setup_global_gtt(). Not only should we defer the binding,
but we should also defer the VM list manipulation.

Fixes regression uncovered by commit a2cad9d
Author: Michał Winiarski <michal.winiarski@intel.com>
Date:   Wed Sep 16 11:49:00 2015 +0200

    drm/i915/gtt: Do not initialize drm_mm twice.

Whilst I am here remove the duplicate work leaving dangling pointers
from the error path...

v2: Typos galore before coffee.

Reported-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92099
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>
Tested-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_gem_gtt.c

@@ -2533,7 +2533,6 @@ static int ggtt_bind_vma(struct i915_vma *vma,
 		 * the bound flag ourselves.
 		 */
 		vma->bound |= GLOBAL_BIND;
-
 	}
 
 	if (dev_priv->mm.aliasing_ppgtt && flags & LOCAL_BIND) {
@@ -2657,6 +2656,7 @@ static int i915_gem_setup_global_gtt(struct drm_device *dev,
 			return ret;
 		}
 		vma->bound |= GLOBAL_BIND;
+		list_add_tail(&vma->mm_list, &ggtt_vm->inactive_list);
 	}
 
 	/* Clear any non-preallocated blocks */

drivers/gpu/drm/i915/i915_gem_stolen.c

@@ -584,7 +584,7 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
 	vma = i915_gem_obj_lookup_or_create_vma(obj, ggtt);
 	if (IS_ERR(vma)) {
 		ret = PTR_ERR(vma);
-		goto err_out;
+		goto err;
 	}
 
 	/* To simplify the initialisation sequence between KMS and GTT,
@@ -598,23 +598,19 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
 		ret = drm_mm_reserve_node(&ggtt->mm, &vma->node);
 		if (ret) {
 			DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
-			goto err_vma;
+			goto err;
 		}
-	}
 
-	vma->bound |= GLOBAL_BIND;
+		vma->bound |= GLOBAL_BIND;
+		list_add_tail(&vma->mm_list, &ggtt->inactive_list);
+	}
 
 	list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);
-	list_add_tail(&vma->mm_list, &ggtt->inactive_list);
 	i915_gem_object_pin_pages(obj);
 
 	return obj;
 
-err_vma:
-	i915_gem_vma_destroy(vma);
-err_out:
-	i915_gem_stolen_remove_node(dev_priv, stolen);
-	kfree(stolen);
+err:
 	drm_gem_object_unreference(&obj->base);
 	return NULL;
 }